[求助]新手求助~（关于初级的神经网络问题） [复制链接]

各位大虾，我在网上看到的教程里的一个程序段，本来想要试试看的： aaFt=7(K  
net=newff([-1 2; 0 5],[3,1],{'tansig','purelin'},'traingd'); YFs!,fw'  
net.trainParam.show = 50; wQN/MYF[  
net.trainParam.lr = 0.05; @xN)mi  
net.trainParam.epochs = 300; >
jpkR  
net.trainParam.goal = 1e-5; z460a[Wl  
p = [-1 -1 2 2;0 5 0 5]; l6< bV#_qe  
t = [-1 -1 1 1]; tQcn%CK  
net=train(net,p,t); X>ck.}F  
TRAINGD, Epoch 0/300, MSE 1.59423/1e-05, Gradient 2.76799/1e-10 ]McDN[h:  
TRAINGD, Epoch 50/300, MSE 0.00236382/1e-05, Gradient 0.0495292/1e-10 6|]e}I@<2  
TRAINGD, Epoch 100/300, MSE 0.000435947/1e-05, Gradient 0.0161202/1e-10 <{1=4PA  
TRAINGD, Epoch 150/300, MSE 8.68462e-05/1e-05, Gradient 0.00769588/1e-10 \mDBOC0eK  
TRAINGD, Epoch 200/300, MSE 1.45042e-05/1e-05, Gradient 0.00325667/1e-10 G*rlU  
TRAINGD, Epoch 211/300, MSE 9.64816e-06/1e-05, Gradient 0.00266775/1e-10 M]A!jWtE  
TRAINGD, Performance goal met. 9NausE40  
a = sim(net,p) n{xL1A=9  
plot(p,t,p,a,'o') ?=%#lZ&?  
但是为什么老是报错： |/O_AnGI  
??? Input argument "net" is undefined. e2L4E8ST<